It is well known that trans-1,2-dichloroethylene, a flammable cleaning agent, has fair solvency with a wide variety of difficult soils found in the electronics and refrigeration industries. It is further known that mixtures of trans-1,2-dichloroethylene and halocarbons have utility in cleaning applications. For example, trans-1,2-dichloroethylene blended with chlorofluorcarbon (“CFC”)-113 (CF2ClCFCl2) in compositions formerly known as Freon® MCA and Freon® SMT. In the late 1980's, it was postulated that chlorofluorcarbons posed the risk of potential environmental problems (i.e. stratospheric ozone depletion and global warming). Notably, CFC-113 is an alleged depletor of stratospheric ozone. In view of the potential environmental problems associated with stratospheric ozone depletion, the above Freon® products were considered transitional materials possessing properties that make them useful substitutes for chlorofluorocarbons, while research for CFC-substitutes was conducted.
Additionally, trans-1,2-dichloroethylene has been reported to form azeotropes and azeotrope-like compositions with fluorocarbons and other solvents, as well as with 1,1,1,2,3,4,4,5,5,5-decafluoropentane, and alcohols, such as methanol and ethanol. However, the cleaning ability of these azeotrope-like compositions is compromised due to the minor amounts of trans-1,2-dichloroethylene and alcohol present.
Accordingly, users of industrial cleaning agents are faced with the dilemma: how does one find an environmentally acceptable alternative that retains non-flammability-without sacrificing cleaning power? Highly fluorinated solvents meet the environmental and. safety requirements, yet they are relatively weak solvents.
The present invention is advantageous in that it provides cleaning agents that are non-ozone depleting, low in global warming, non-flammable, and do not sacrifice cleaning power. Another advantage of the invention is that it departs from the paradigm that necessitates the use of azeotropes, wherein the evaporation rate of all components is essentially the same through the use of phased evaporation of the flammable and inerting components. The compositions of the present invention are useful in cleaning printed circuit cards or flushing oil and particles from refrigeration or air conditioning systems. Another advantage of the present invention is the process of depositing mold release agent on the surface of a mold.
For the foregoing reasons there is a need for cleaning agents that are non-ozone depleting, low in global warming, non-flammable, and do not sacrifice cleaning power. These and other features, aspects, and advantages of the present invention will become more apparent with reference to the following Summary, Description and appended claims.